Optical imaging lens

1. An optical imaging lens comprising, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, and a seventh lens element arranged along an optical axis, each lens element having an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein:

the object-side surface of the first lens element has a convex portion in a vicinity of the optical axis and the image-side surface has an concave portion in the vicinity of the optical axis;

the second and fifth lens elements have a refractive power;

the image-side surface of the third lens element has a concave portion in the vicinity of the optical axis and an concave portion in the vicinity of an outer circumference;

the object-side surface of the fourth lens element has a concave portion in the vicinity of the optical axis and the image-side surface has a convex portion in the vicinity of the optical axis;

the image-side surface of the sixth lens element has a convex portion in the vicinity of the optical axis;

the object-side surface of the seventh lens element has a convex portion in the vicinity of the optical axis and image-side surface has a convex portion in the vicinity of the outer circumference;

the optical imaging lens only has seven lens elements having a refractive power; and

an effective focal length of the optical imaging lens is defined as EFL, a thickness of the seventh lens element along the optical axis is defined as T7, and EFL and T7 satisfy the relation:

EFL/ T 7≦3.

2. The optical imaging lens of claim 1 , wherein an air gap between the second and third lens elements along the optical axis is defined as G23 and an air gap between the third and fourth lens elements along the optical axis is defined as G34, and wherein G23 and G34 satisfy the relation:

G 23/ G 34≦1.2.

3. The optical imaging lens of claim 1 , wherein a thickness of the second lens element along the optical axis is defined as T2 and an air gap between the second and third lens elements along the optical axis is defined as G23, and wherein T2 and G23 satisfy the relation:

T 2/ G 23≦15.

4. The optical imaging lens of claim 1 , wherein a thickness of the second lens element along the optical axis is defined as T2 and a thickness of the fourth lens element along the optical axis is defined as T4, and wherein T2 and T4 satisfy the relation:

T 2/ T 4≦2.0.

5. The optical imaging lens of claim 1 , wherein an air gap between the third and fourth lens elements along the optical axis is defined as G34 and an air gap between the fourth and fifth lens elements along the optical axis is defined as G45, and wherein G34 and G45 satisfy the relation:

G 34/ G 45≦30.

6. The optical imaging lens of claim 1 , wherein a sum of thicknesses of the first, second, third, fourth, fifth, sixth, and seventh lens elements along the optical axis is defined as ALT, and wherein ALT and EFL satisfy the relation:

ALT/EFL≦6.

7. An optical imaging lens comprising, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, an aperture stop, a fourth lens element, a fifth lens element, a sixth lens element, and a seventh lens element arranged along an optical axis, each lens element having an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein:

the object-side surface of the first lens element has a convex portion in a vicinity of the optical axis and a convex portion in a vicinity of an outer circumference;

the second and fifth lens elements have a refractive power;

the object-side surface of the third lens element has a convex portion in the vicinity of the optical axis and a convex portion in the vicinity of the outer circumference;

the object-side surface of the fourth lens element has a concave portion in the vicinity of the optical axis;

the image-side surface of the sixth lens element has a convex portion in the vicinity of the outer circumference;

the object-side surface of the seventh lens element has a convex portion in the vicinity of the optical axis and image-side surface has a convex portion in the vicinity of the outer circumference;

the optical imaging lens only has seven lens elements having a refractive power; and

an effective focal length of the optical imaging lens is defined as EFL, an air gap between the first and second lens elements along the optical axis is defined as G12, and EFL and G12 satisfy the relation:

EFL/ G 12≦10.

8. The optical imaging lens of claim 7 , wherein a thickness of the fifth lens element along the optical axis is defined as T5 and a thickness of the sixth lens element along the optical axis is defined as T6, and wherein T5 and T6 satisfy the relation:

T 5/ T 6≦4.0.

9. The optical imaging lens of claim 7 , wherein an air gap between the second and third lens elements along the optical axis is defined as G23 and an air gap between the sixth and seventh lens elements along the optical axis is defined as G67, and wherein G23 and G67 satisfy the relation:

G 23/ G 67≦25.

10. The optical imaging lens of claim 7 , wherein a thickness of the first lens element along the optical axis is defined as T1 and a thickness of the second lens element along the optical axis is defined as T2, and wherein T1 and T2 satisfy the relation:

T 1/ T 2≦2.5.

11. The optical imaging lens of claim 7 , wherein a sum of air gaps between the first lens element through the seventh lens element along the optical axis is defined as AAG and an air gap between the third and fourth lens elements is defined as G34, and wherein AAG and G34 satisfy the relation:

AAG/ G 34≦6.

12. The optical imaging lens of claim 7 , wherein a sum of thicknesses of the first, second, third, fourth, fifth, sixth, and seventh lens elements along the optical axis is defined as ALT and a sum of air gaps between the first lens element through the seventh lens element along the optical axis is defined as AAG, and wherein ALT and AAG satisfy the relation:

ALT/AAG≦5.

13. An optical imaging lens comprising, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, and a seventh lens element arranged along an optical axis, each lens element having an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein:

the object-side surface of the first lens element has a convex portion in a vicinity of an outer circumference and the image-side surface has a concave portion in a vicinity of the optical axis;

the second and fifth lens elements have a refractive power;

the object-side surface of the third lens element has a convex portion in the vicinity of the optical axis and the image-side surface has a concave portion in the vicinity of the optical axis;

the fourth lens element has a positive refractive power and the image-side surface has a convex image-side surface in the vicinity of the optical axis;

the image-side surface of the sixth lens element has a convex portion in the vicinity of the optical axis and a convex portion in a vicinity of the outer circumference;

the image-side surface of the seventh lens element has a convex portion in the vicinity of the optical axis and a convex portion in a vicinity of the outer circumference;

the optical imaging lens only has seven lens elements having a refractive power; and

an air gap between the first and second lens elements along the optical axis is defined as G12, an air gap between the second and third lens elements along the optical axis is defined as G23, and G12 and G23 satisfy the relation:

G 12/ G 23≦20.

14. The optical imaging lens of claim 13 , wherein a thickness of the sixth lens element along the optical axis is defined as T6, and wherein T6 and G23 satisfy the relation:

T 6/ G 23≦25.

15. The optical imaging lens of claim 13 , wherein a thickness of the first lens element along the optical axis is defined as T1 and an air gap between the sixth and seventh lens elements along the optical axis is defined as G67, and wherein T1 and G67 satisfy the relation:

T 1/ G 67≦30.

16. The optical imaging lens of claim 13 , wherein a thickness of the third lens element along the optical axis is defined as T3 and a thickness of the seventh lens element along the optical axis is defined as T7, and wherein T3 and T7 satisfy the relation:

T 3/ T 7≦1.5.

17. The optical imaging lens of claim 13 , wherein a sum of air gaps between the first lens element through the seventh lens element along the optical axis is defined as AAG and an effective focal length of the optical imaging lens is defined as EFL, and wherein AAG and EFL satisfy the relation:

AAG/EFL≦3.5.